user
Write a creative story given the following facts.

Now complete the following instance -
Input: Theme: Friendship
Character: Cowboy
Setting: Mountain
Output:
assistant
Once upon a time there was a cowboy who lived in the mountains. He had no family and a few friends, but what he did have was an incredible amount of tenacity and determination. 

One day, a wild horse with a black coat and rusty mane appeared on the mountain. The cowboy set out to tame it, day after day, and eventually the horse warmed up to him. Soon, the two of them could be found traversing the mountain together, the cowboy atop the horse's back. 

The cowboy had developed an unlikely and unshakeable bond with the horse. No matter the obstacle, the horse was always there for him. They became more than just master and animal; they became the best of friends.